Circuit Description
The body control module (BCM) controls the instrument panel (I/P) courtesy lamps through the courtesy lamps supply voltage circuit. The BCM grounds the courtesy lamps low control circuit which completes the I/P courtesy lamps ground circuit, and the lights illuminate.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2618 Courtesy Lamps Supply Voltage Circuit High
Conditions for Running the DTC
The BCM must command the courtesy lamps feature ON.
Conditions for Setting the DTC
| • | The BCM detects a high when the output should be low in the courtesy lamps supply voltage circuit. |
| • | The condition above must be present for more than 0.3 seconds. |
Action Taken When the DTC Sets
The BCM stores DTC B2618 in memory.
Conditions for Clearing the DTC
| • | A current DTC B2618 will clear if the short to battery in the courtesy lamps supply voltage circuit is no longer detected by the BCM. |
| • | A history DTC B2618 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present and no other BCM faults are detected. |
Diagnostic Aids
| • | If the DTC B2618 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | The following conditions may cause an intermittent malfunction to occur: |
| - | An intermittent short to battery in the courtesy lamps supply voltage circuit |
| - | Either I/P courtesy lamp is intermittently shorted to battery internally. |
| - | The BCM is intermittently shorted to battery internally. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Do the footwell lamps turn ON and OFF with each command? | Go to Step 10 | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 11 |
4 |
Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 5 |
5 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 |
6 | Test the courtesy lamps low control circuit for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
7 | Test the courtesy lamps low control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
8 | Inspect for poor connections at each I/P courtesy lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
9 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
10 | Inspect for short to battery voltage on courtesy lamp supply voltage circuit. Refer to Testing for a Short to Voltage . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
11 | Repair the high resistance or an open in the courtesy lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the inoperative I/P courtesy lamp. Refer to Instrument Panel Courtesy Lamp Bulb Replacement . Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 |
Does the DTC reset? | Go to Step 2 | System OK |
